1. Field of the Invention
The present invention relates to a servo writer for writing a servo signal in a magnetic tape, and a write and inspection method of the servo signal.
2. Description of the Related Art
Conventionally, a magnetic tape is widely used as a recording medium for recording/reproducing data. In the magnetic tape are formed many data tracks for recording data in lateral directions of the magnetic tape in order to heighten a recording density per unit area. In the magnetic tape, because minute movements in the lateral directions are repeated in running due to various reasons, it becomes difficult for a recording/reproducing head to completely trace the data tracks in recording/reproducing data. Consequently, in recording/reproducing data an apparatus for recording/reproducing this kind of magnetic tape makes it a reference a servo signal written in the magnetic tape in advance, and dynamically controls a tracking of the recording/reproducing head for the magnetic tape. In other words, the apparatus reads a servo signal by a servo read head integrally formed with the recording/reproducing head, detects a displacement of a position of the recording/reproducing head in the lateral directions of the magnetic tape, and moves the recording/reproducing head or controls a running state of the magnetic tape so as to modify the displacement. The servo signal is written along a running direction in advance by a dedicated servo writer (see paragraphs 0002 to 0005 of JP 2003-141836A).
Because the servo signal is written in a magnetic tape with a different pattern according to a product class of the magnetic tape, a servo writer for writing the servo signal is specialized, matching each of the product class. Therefore, in order to divert a servo writer used for writing the servo signal in one product class of a magnetic tape to a writing of a servo signal in another product class of a magnetic tape, it becomes necessary to revamp the servo writer and to change a control circuit in order to change a standard for inspecting and evaluating a servo signal to be written and a servo signal written. In other words, in order to write a servo signal corresponding to a magnetic tape different in a product class are needed a work for refixing a servo write head or its circuit and a reproducing head or its circuit, and a change of conditions thereof. Therefore, it is necessary to stop the servo writer for a long time, and there is a problem in productivity and cost of the magnetic tape. On the other hand, in order to avoid the problem due to such the work of refixing the servo write head, although servo writers corresponding to each product classes are respectively prepared as many as a number of the product classes, there is a problem in equipment cost and magnetic tape cost.
But these years it is requested to produce a wide variety of products timely by a proper amount because of a format diversification of a magnetic tape market. In order to efficiently produce such different product classes of magnetic tapes, it is also requested that a servo writer for writing a servo signal in the magnetic tapes can flexibly handle a change of a product class, switch such a servo write head, write a proper servo signal in every magnetic tape, and inspect the servo signal written.
Consequently, it is strongly requested a servo writer that can write a proper servo signal for each magnetic tape different in a product class thereof, and inspect the servo signal written; and a write and inspection method of the servo signal using the servo writer.